Numerous coated confectionaries are available. Many confectionaries, such as M&M's or chewing gum balls, have a hard shell sugar coating. Some products, such as M&M's CRISPIES, have a hard center, with a chocolate covering followed by a hard shell coating. Other products include a chewy center with a hard candy shell. Thus confectionary products with multiple layers and coatings are known.
However, producing a product with a chewy center and a hard shell can cause processing difficulties, especially with controlling the crystallinity and moisture levels in the product. It is difficult to coat a soft center with a hard coating. Also, hard shells can be brittle and difficult to package without damaging the product or causing the hard shell to chip off or break.